<!DOCTYPE html>
<html lang="zh-CN">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>绝对定位的参考点_body</title>
    <style>
        *{
            margin: 0;
            padding: 0;
        }
        p{
            width: 100px;
            height: 100px;
            background: cyan;
        }
        .left_top{
            position: absolute;
            left: 100px;
            top: 100px;
        }
        .right_top{
            position: absolute;
            right: 100px;
            top: 100px;
        }
        .left_bottom{
            position: absolute;
            left: 100px;
            bottom: 100px;
        }
        .right_bottom{
            position: absolute;
            right: 100px;
            bottom: 100px;
        }
    </style>
</head>
<body>
    <p class="left_top"></p>
    <p class="right_top"></p>
    <p class="left_bottom"></p>
    <p class="right_bottom"></p>
</body>
</html>